making hop quantity adjustments based on alpha

[jamsterson]

Our house IPA just uses two hop varietals, a high-alpha bittering and a another variety for finishing at 15, 10, 5 min and at flameout. We buy hops on lupulinexchange and so the alpha % varies. We make weight adjustments based on the alpha % of the hops we have on hand, being careful to match the same IBU contribution of each addition called for by our recipe.

Rethinking this because if our finishing hops are under 5% alpha it creates a ton of transfer waste because we've thrown so much in. Thinking of keeping finishing hops additions to quantity sufficient to provide provide the hoppy character we're shooting without regard to alpha, and making adjustments only to our bittering hop quantity to keep the total IBUs consistent.

How do others approach this?

Note that we're a small brewery with no lab.

[blonberg]

I do something similar to what you're proposing changing to. I watch my alpha for bittering, and try to account for normal hop degradation, but don't worry about alpha for flavor hops or dry hops. I'm in a similar situation, at a small brewpub without a lab. This method hasn't created any discernible quality issues for me.